<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    * {
      margin: 0;
      padding: 0;
    }
    #box {
      position: fixed;
      top: 0;
      bottom: 0;
      left: 0;
      right: 0;
      background-color: #000;
      color: #000;
    }
    .btn-box {
      position: absolute;
      left: 50%;
      top: 50%;
      transform: translate(-50%, -50%);
      color: fff;
      z-index: 111;
    }
  </style>
</head>
<body>
	<div id="box"></div>
	<div class="btn-box"><button id="btn">修改值</button></div>
	<script>

	async function demo (count) {
		const data = []
		let current = 0;
		return new Promise((resolve) => {
			const rec = () => {
				setTimeout(function () {
					const value = current
					data.push({
						value: value,
						preData: current === 0 ? null : data[current - 1].value
					})
					current++
					if (current === count) {
						return resolve(data)
					}
					rec()
				}, 1000)
			}
			rec()
		})
	}

	demo(5).then(res => {
		console.log(res)
	})

	</script>
</body>
</html>